1 /*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 */
21
22 #include "varattrs.h"
23
24 #ifndef lint
25 static const char copyright[] _U_ =
26 "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
27 The Regents of the University of California. All rights reserved.\n";
28 #endif
29
30 /*
31 * Tests how select() and poll() behave on the selectable file descriptor
32 * for a pcap_t.
33 *
34 * This would be significantly different on Windows, as it'd test
35 * how WaitForMultipleObjects() would work on the event handle for a
36 * pcap_t.
37 */
38 #include <pcap.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <stdarg.h>
43 #include <unistd.h>
44 #include <errno.h>
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_SELECT_H
47 #include <sys/select.h>
48 #else
49 #include <sys/time.h> /* older UN*Xes */
50 #endif
51 #include <poll.h>
52
53 #include "pcap/funcattrs.h"
54
55 static char *program_name;
56
57 /* Forwards */
58 static void countme(u_char *, const struct pcap_pkthdr *, const u_char *);
59 static void PCAP_NORETURN usage(void);
60 static void PCAP_NORETURN error(const char *, ...) PCAP_PRINTFLIKE(1, 2);
61 static void warning(const char *, ...) PCAP_PRINTFLIKE(1, 2);
62 static char *copy_argv(char **);
63
64 static pcap_t *pd;
65
66 int
main(int argc,char ** argv)67 main(int argc, char **argv)
68 {
69 register int op;
70 bpf_u_int32 localnet, netmask;
71 register char *cp, *cmdbuf, *device;
72 int doselect, dopoll, dotimeout, dononblock, quiet;
73 const char *mechanism;
74 struct bpf_program fcode;
75 char ebuf[PCAP_ERRBUF_SIZE];
76 pcap_if_t *devlist;
77 int selectable_fd = -1;
78 const struct timeval *required_timeout;
79 int status;
80 int packet_count;
81
82 device = NULL;
83 doselect = 0;
84 dopoll = 0;
85 mechanism = NULL;
86 dotimeout = 0;
87 dononblock = 0;
88 quiet = 0;
89 if ((cp = strrchr(argv[0], '/')) != NULL)
90 program_name = cp + 1;
91 else
92 program_name = argv[0];
93
94 opterr = 0;
95 while ((op = getopt(argc, argv, "i:sptnq")) != -1) {
96 switch (op) {
97
98 case 'i':
99 device = optarg;
100 break;
101
102 case 's':
103 doselect = 1;
104 mechanism = "select() and pcap_dispatch()";
105 break;
106
107 case 'p':
108 dopoll = 1;
109 mechanism = "poll() and pcap_dispatch()";
110 break;
111
112 case 't':
113 dotimeout = 1;
114 break;
115
116 case 'n':
117 dononblock = 1;
118 break;
119
120 case 'q':
121 quiet = 1;
122 break;
123
124 default:
125 usage();
126 /* NOTREACHED */
127 }
128 }
129
130 if (doselect && dopoll) {
131 fprintf(stderr, "selpolltest: choose select (-s) or poll (-p), but not both\n");
132 return 1;
133 }
134 if (dotimeout && !doselect && !dopoll) {
135 fprintf(stderr, "selpolltest: timeout (-t) requires select (-s) or poll (-p)\n");
136 return 1;
137 }
138 if (device == NULL) {
139 if (pcap_findalldevs(&devlist, ebuf) == -1)
140 error("%s", ebuf);
141 if (devlist == NULL)
142 error("no interfaces available for capture");
143 device = strdup(devlist->name);
144 pcap_freealldevs(devlist);
145 }
146 *ebuf = '\0';
147 pd = pcap_open_live(device, 65535, 0, 1000, ebuf);
148 if (pd == NULL)
149 error("%s", ebuf);
150 else if (*ebuf)
151 warning("%s", ebuf);
152 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
153 localnet = 0;
154 netmask = 0;
155 warning("%s", ebuf);
156 }
157 cmdbuf = copy_argv(&argv[optind]);
158
159 if (pcap_compile(pd, &fcode, cmdbuf, 1, netmask) < 0)
160 error("%s", pcap_geterr(pd));
161 if (pcap_setfilter(pd, &fcode) < 0)
162 error("%s", pcap_geterr(pd));
163
164 if (doselect || dopoll) {
165 /*
166 * We need either an FD on which to do select()/poll()
167 * or, if there isn't one, a timeout to use in select()/
168 * poll().
169 */
170 selectable_fd = pcap_get_selectable_fd(pd);
171 if (selectable_fd == -1) {
172 printf("Listening on %s, using %s, with a timeout\n",
173 device, mechanism);
174 required_timeout = pcap_get_required_select_timeout(pd);
175 if (required_timeout == NULL)
176 error("select()/poll() isn't supported on %s, even with a timeout",
177 device);
178
179 /*
180 * As we won't be notified by select() or poll()
181 * that a read can be done, we'll have to periodically
182 * try reading from the device every time the required
183 * timeout expires, and we don't want those attempts
184 * to block if nothing has arrived in that interval,
185 * so we want to force non-blocking mode.
186 */
187 dononblock = 1;
188 } else {
189 printf("Listening on %s, using %s\n", device,
190 mechanism);
191 required_timeout = NULL;
192 }
193 } else
194 printf("Listening on %s, using pcap_dispatch()\n", device);
195
196 if (dononblock) {
197 if (pcap_setnonblock(pd, 1, ebuf) == -1)
198 error("pcap_setnonblock failed: %s", ebuf);
199 }
200 if (doselect) {
201 for (;;) {
202 fd_set setread, setexcept;
203 struct timeval seltimeout;
204 struct timeval *timeoutp;
205
206 FD_ZERO(&setread);
207 if (selectable_fd != -1) {
208 FD_SET(selectable_fd, &setread);
209 FD_ZERO(&setexcept);
210 FD_SET(selectable_fd, &setexcept);
211 }
212 required_timeout = pcap_get_required_select_timeout(pd);
213 if (dotimeout) {
214 seltimeout.tv_sec = 0;
215 if (required_timeout != NULL &&
216 required_timeout->tv_usec < 1000)
217 seltimeout.tv_usec = required_timeout->tv_usec;
218 else
219 seltimeout.tv_usec = 1000;
220 timeoutp = &seltimeout;
221 } else if (required_timeout != NULL) {
222 seltimeout = *required_timeout;
223 timeoutp = &seltimeout;
224 } else {
225 timeoutp = NULL;
226 }
227 status = select((selectable_fd == -1) ?
228 0 : selectable_fd + 1, &setread, NULL, &setexcept,
229 timeoutp);
230 if (status == -1) {
231 printf("Select returns error (%s)\n",
232 strerror(errno));
233 } else {
234 if (!quiet) {
235 if (status == 0)
236 printf("Select timed out: ");
237 else{
238 printf("Select returned a descriptor: ");
239 if (FD_ISSET(selectable_fd, &setread))
240 printf("readable, ");
241 else
242 printf("not readable, ");
243 if (FD_ISSET(selectable_fd, &setexcept))
244 printf("exceptional condition\n");
245 else
246 printf("no exceptional condition\n");
247 }
248 }
249 packet_count = 0;
250 status = pcap_dispatch(pd, -1, countme,
251 (u_char *)&packet_count);
252 if (status < 0)
253 break;
254 /*
255 * Don't report this if we're using a
256 * required timeout and we got no packets,
257 * because that could be a very short timeout,
258 * and we don't want to spam the user with
259 * a ton of "no packets" reports.
260 */
261 if (status != 0 || packet_count != 0 ||
262 required_timeout != NULL) {
263 printf("%d packets seen, %d packets counted after select returns\n",
264 status, packet_count);
265 }
266 }
267 }
268 } else if (dopoll) {
269 for (;;) {
270 struct pollfd fd;
271 int polltimeout;
272
273 fd.fd = selectable_fd;
274 fd.events = POLLIN;
275 required_timeout = pcap_get_required_select_timeout(pd);
276 if (dotimeout)
277 polltimeout = 1;
278 else if (required_timeout != NULL &&
279 required_timeout->tv_usec >= 1000)
280 polltimeout = (int)(required_timeout->tv_usec/1000);
281 else
282 polltimeout = -1;
283 status = poll(&fd, (selectable_fd == -1) ? 0 : 1, polltimeout);
284 if (status == -1) {
285 printf("Poll returns error (%s)\n",
286 strerror(errno));
287 } else {
288 if (!quiet) {
289 if (status == 0)
290 printf("Poll timed out\n");
291 else {
292 printf("Poll returned a descriptor: ");
293 if (fd.revents & POLLIN)
294 printf("readable, ");
295 else
296 printf("not readable, ");
297 if (fd.revents & POLLERR)
298 printf("exceptional condition, ");
299 else
300 printf("no exceptional condition, ");
301 if (fd.revents & POLLHUP)
302 printf("disconnect, ");
303 else
304 printf("no disconnect, ");
305 if (fd.revents & POLLNVAL)
306 printf("invalid\n");
307 else
308 printf("not invalid\n");
309 }
310 }
311 packet_count = 0;
312 status = pcap_dispatch(pd, -1, countme,
313 (u_char *)&packet_count);
314 if (status < 0)
315 break;
316 /*
317 * Don't report this if we're using a
318 * required timeout and we got no packets,
319 * because that could be a very short timeout,
320 * and we don't want to spam the user with
321 * a ton of "no packets" reports.
322 */
323 if (status != 0 || packet_count != 0 ||
324 required_timeout != NULL) {
325 printf("%d packets seen, %d packets counted after poll returns\n",
326 status, packet_count);
327 }
328 }
329 }
330 } else {
331 for (;;) {
332 packet_count = 0;
333 status = pcap_dispatch(pd, -1, countme,
334 (u_char *)&packet_count);
335 if (status < 0)
336 break;
337 printf("%d packets seen, %d packets counted after pcap_dispatch returns\n",
338 status, packet_count);
339 }
340 }
341 if (status == -2) {
342 /*
343 * We got interrupted, so perhaps we didn't
344 * manage to finish a line we were printing.
345 * Print an extra newline, just in case.
346 */
347 putchar('\n');
348 }
349 (void)fflush(stdout);
350 if (status == -1) {
351 /*
352 * Error. Report it.
353 */
354 (void)fprintf(stderr, "%s: pcap_dispatch: %s\n",
355 program_name, pcap_geterr(pd));
356 }
357 pcap_close(pd);
358 exit(status == -1 ? 1 : 0);
359 }
360
361 static void
countme(u_char * user,const struct pcap_pkthdr * h _U_,const u_char * sp _U_)362 countme(u_char *user, const struct pcap_pkthdr *h _U_, const u_char *sp _U_)
363 {
364 int *counterp = (int *)user;
365
366 (*counterp)++;
367 }
368
369 static void
usage(void)370 usage(void)
371 {
372 (void)fprintf(stderr, "Usage: %s [ -sptnq ] [ -i interface ] [expression]\n",
373 program_name);
374 exit(1);
375 }
376
377 /* VARARGS */
378 static void
error(const char * fmt,...)379 error(const char *fmt, ...)
380 {
381 va_list ap;
382
383 (void)fprintf(stderr, "%s: ", program_name);
384 va_start(ap, fmt);
385 (void)vfprintf(stderr, fmt, ap);
386 va_end(ap);
387 if (*fmt) {
388 fmt += strlen(fmt);
389 if (fmt[-1] != '\n')
390 (void)fputc('\n', stderr);
391 }
392 exit(1);
393 /* NOTREACHED */
394 }
395
396 /* VARARGS */
397 static void
warning(const char * fmt,...)398 warning(const char *fmt, ...)
399 {
400 va_list ap;
401
402 (void)fprintf(stderr, "%s: WARNING: ", program_name);
403 va_start(ap, fmt);
404 (void)vfprintf(stderr, fmt, ap);
405 va_end(ap);
406 if (*fmt) {
407 fmt += strlen(fmt);
408 if (fmt[-1] != '\n')
409 (void)fputc('\n', stderr);
410 }
411 }
412
413 /*
414 * Copy arg vector into a new buffer, concatenating arguments with spaces.
415 */
416 static char *
copy_argv(register char ** argv)417 copy_argv(register char **argv)
418 {
419 register char **p;
420 register size_t len = 0;
421 char *buf;
422 char *src, *dst;
423
424 p = argv;
425 if (*p == 0)
426 return 0;
427
428 while (*p)
429 len += strlen(*p++) + 1;
430
431 buf = (char *)malloc(len);
432 if (buf == NULL)
433 error("copy_argv: malloc");
434
435 p = argv;
436 dst = buf;
437 while ((src = *p++) != NULL) {
438 while ((*dst++ = *src++) != '\0')
439 ;
440 dst[-1] = ' ';
441 }
442 dst[-1] = '\0';
443
444 return buf;
445 }
446